Hydraulic control mechanism



Sept. 8 1942 H. c. CLAY 2,295,161

HYDRAULIC CONTROL MECHANISM Filed March 7, 1939 4 Sheets-Sheet l 6 OR. al'l' l I BY a J a;

v63km! 0342761.

' ATTORNEY J.

Sept. 8, 1942. H. c.c|-.A

HYDRAULIC CONTROL MECHANISM 4 Sheets-Sheet 2 I II II III' Filed March 7.1939 III/III,

I INVENTOR. BY 62/9/75 (f (la y,

634%! v ATTORNEY3.

' 1942- H. c. CLAY 2,295,161

HYDRAULIC CONTROL MECHANISM Filed March 7, 1939 4 Sheets-Sheet 3IINVENTOR.

ATTORNEYS.

Sept. 8, 1942. H. c. CLAY 2,295,161

HYDRAULIC CONTROL MECHANISM' 7 Filed March 7, 1939 4 Sheets-Sheet 4(ONT/70L V4! V5 MOTOFF Patented Sept. 8, 1942 PATET FEE Harry .0. Clay,Columbus, Ind., assignor to Reeves Pulley Company, Columbus, Ind., acorporation of Indiana Application March 7, 1939, Serial No. 260,451

8 Claims.

The present application relates to a hydraulic control mechanism, andthe mechanism is shown, in the present application, associated with aVariable speed transmission of a particular type. The primary object ofthe invention is to provide a hydraulic control mechanism for shifting.a movable element, said mechanism comprising a constantly driven rotarypump for supplying fluid under pressure to a fluid motor which, in turn,upon actuation of a valve, will operate to shift the movable controlledmember to a degree and in a direction dependent upon the degree anddirection of movement of the valve. A feature of the invention is theprovision of conduit means connecting the pump with the motor and with afluid reservoir in such a manner that, upon operation of the pump in onedirection, a single flow path from the reservoir through the pump to themotor will be established, while, upon operation of the pump in theopposite direction, a different single flow path will be establishedfrom the reservoir, through the pump, and to the motor. While thecontrol mechanism is illustrated in association with a particular typeof variable speed transmission, it will be recognized that the controlmechanism is applicable to other types of variable speed transmissions,and to the control of different mechanisms, in which a desired end isattained by positive movement of a controlled member in one direction orthe other.

Further objects of the invention will appear as the descriptionproceeds.

To the accomplishment of the above and related objects, my invention maybe embodied in the form illustrated in the accompanying drawings,attention being called to the fact, however, that the drawings areillustrative only, and that change may be made in the specificconstruction illustrated and described, so long as the scope of theappended claims is not violated.

Fig. 1 is a plan, parts of the casing being broken away for clarity ofillustration, showing my control associated with one type of variablespeed transmission;

Fig. 2 is a somewhat enlarged side elevation of the said mechanism,looking from the left of Fig. 1, the housing of the control unit beingshown in section;

Fig. 3 is a plan view of the control unit, the housing being shown insection;

Fig. 4 is an enlarged sectional View through the fluid motor, takensubstantially on the line la-4 of Fig. 2, and looking in the directionof the arrows;

Fig. 5 is a sectional View of the variable speed. 55

(Cl. T L-230.17),

transmission with which the control mechanism is shown associated;

Fig. 6 is an enlarged end elevation of the fluid motor cylinder andvalve mechanism, the cylinder head being removed;

Fig. '7 is a section taken substantially on the line 1-4 of Fig. 6 andlooking in the direction of the arrows;

Fig. 8 is an enlarged view of the telescopic tube through which fluid issupplied from the pump to the valve housing; and

Fig. 9 is a schematic layout of the pump and motor.

Referring more particularly to the drawings, it will be seen that I haveillustrated a base upon which is mounted an electric motor H, upon thespindle of which is supported an expansi-ble V-pulley comprising themating coned discs l 2' and I3. Preferably, the transmission will beenclosed within a housing l4 in which is journalled the driven shaft Iof the'transmission, said shaft carrying an expansible V-pulleycomprising the discs I6 and IT. From an inspection of Fig. 5, it will beseen that the disc i2 is intended to be fixedly mounted upon the spindleof motor II, and is provided with an elongated hub upon which isslidably mounted the hub 2| of the mating disc 53. Said hub 2| carriesone race 22 of a thrust bearing, the outer race 23 of which is providedwith a pair of diametrically oppositely projecting pins 24 upon which isswiveled an equalizer ring 25.

Similarly, the disc I6 is fixed to the driven shaft l5 and is providedwith an elongated hub 26 upon which is slidably mounted the disc il, aspring l8 being sleeved over the hub 21 of the disc 11, and bearingagainst a stop nut 28 mounted on the hub 26, to urge said disc I!constantly resiliently toward the disc IS. The two pulleys are'drivinglyconnected by a V-belt 19.

The equalizer ring is provided with two oppositely projecting radialpins 30, ninety degrees removed from the pins 24, to which are swiveledthe arms 3| of a yoke carried by one head 32 of the cylinder 33 of afluid motor forming a part of the hydraulic control mechanism indicatedgenerally by the reference numeral 34.

Sam mechanism is preferably enclosed with a casing 35'which acts as afluid reservoir, and includes a fluid pump 36 of the rotary, reversibletype. The shaft 3! of said pump carries a gear 38 meshing with a pinion39 carried on the hub 20, whereby said pump shaft 31 is constantlydriven by the motor I l at constant speed. Since the transmissionmanufacturer cannot be sure whether his organization will be associatedwith a motor which runs clockwise or with a motor which runscounter-clockwise, it is highly desirable that the pump 36 shall be ofsuch character as to operate when driven in either direction; and thatmeans shall be provided whereby, no matter in which direction the pump36 is driven, fluid will be drawn from the reservoir 35 and dischargedto the fluid motor cylinder 33. I have accomplished that objective bythe system of conduits and check valves disclosed most particularly inFigs. 2, 3, and 9.

The pump 36 is provided with a port 40 which is connected, by a pipe 4|,with the stem of a T-fitting 42, one branch of which communicates with acheck valve 43 so constructed as to permit upward flow onlytherethrough. The other branch of said T-fitting 42 is connected, bypipe 44 and elbow 45, with a check valve 46 so constructed as to permitflow therethrough toward the left only as viewed in Figs. 2 and 9. Theoutlet port of said check valve 46 is connected, by a pipe 41, with onebranch of a four-way fitting 48. A se'cond branch of said fitting isconnected, by pipe 49, with an adjustable relief valve 50; so that,during periods when flow to the fluid motor is cut off, fluid dischargedfrom the pump 36 may be returned to the reservoir through V said reliefvalve 50.

From a third branch of the fitting 48 leads a pipe for supplying fluidto the fluid motor, through a flow path hereinafter to be described.

The opposite port 52 of the pump 36 is connected to a three-way fitting53, one branch of which is connected, through elbow 54 and pipe 55, witha check valve 56 so constructed as to permit flow upwardly therethroughonly. The other branch of said fitting 53 is connected, by pipe 51 andelbow 58, with a check valve 59 so constructed as to permit flowtherethrough to the left only, as viewed in Figs. 2 and 9. A pipe 60connects the outlet of the valve 59 with the fourth branch of thefitting 48.

It follows that, when the pump 36 is driven in one direction, liquidwill be drawn upwardly from the reservoir through the check valve 43, T42, and. pipe 4|, through the pump 36, fitting '53, pipe 51, valve 59,and pipe 60 to the four-way fitting 48, whence it will flow eitherthrough the relief valve 50 or through the supply pipe 5| to the fluidmotor. If the pump 36 is driven in the opposite direction, however,liquid will be drawn upwardly from the reservoir through the valve 56,pipe 55, elbow 54, fitting 53, and port 52 through the pump and, throughport 46, pipe 4|, T 42, pipe 44, elbow 45, valve 46, and pipe 41 to thefitting 48, whence it will flow either through the relief valve 50 orthrough the supply pipe 5| to the fluid motor. This selection of flowpaths, dependent upon the direction of rotation of the pump 36, will beseen to be entirely automatic, requiring no manipulation by theoperator.

A piston rod 6| has one end 62 thereof fixedly mounted in the wall 13 ofthe housing 35, by means of nuts 63; and said piston rod fixedly carriesa piston 64. Said piston 64 is received within the cylinder 33; and itwill be obvious that fluid under pressure, supplied to the cylinder 33,will icause movement of the cylinder with respect to the fixed piston64.

From the wall of the cylinder 33 projects a protuberance indicatedgenerally by the reference numeral 10, and formed to provide a valvehousing H, and a supply tube 12. The valve housing H is formed with abore 83, and the supply tube is formed with a parallel bore having anintermediate enlargement 19 between its ends and 8|. Within theprotuberance 10 are formed two passages 65 and 66 opening paraxiallyinto the bore 83, and leading to opposite ends of the cylinder 33,through passages 61 and 68 respectively formed in the respectivecylinder heads 32 and 69.

The flanged end 14 of an elongated tube 15 which is closed at both ends,is secured fixedly to the wall 13 in any suitable manner. Near its endremote from the flange 14, said tube is provided with a radial inletport 16, to which is connected the discharge end of the pipe 5|, andwhich communicates with the chamber Tl stormed within the tube 15.Intermediate its ends, the tube 15 is formed with one or more radialports 18.

The supply tube 12 is sleeved on the tube 15, the opposite end portions86 and 8| thereof snugly fitting upon the tube 15 and being preferablyprovided with oil sealing grooves, as shown. The assembly 10 is slidableupon the tube 15, moving with the cylinder 33 as said cylinder isreciprocated. The axial extent of the enlarged portion 19 of the bore ofthe supply tube is at least equal to the axial stroke orthe cylinder 33,and the assembly 10 is so associated with the tube 15 that the port 18is always in communication with the enlarged portion 19.

A passage 82 leads from the enlarged portion 19 into the valve housingbore 83. Within said bore is mounted a valve cage 84 provided with anexternal peripheral groove 85 communicating with the passage 82 and witha peripheral series of ports 86 leading into the bore 81 of said cage,in which is reciprocably mounted a valve 88 of the piston type having aplurality of peripheral lands 89, 98, 9|, and 92. Said valve cage isfurther provided with a peripheral series of ports 93 leading from thebore 81 into an external peripheral groove 94 communicating with themouth of the passage 65. Said cage is further formed with an externalperipheral groove 96 communicating with a peripheral series of ports 91leading from the bore 81, and with a discharge port 98 at one end of thevalve housing.

At the opposite side of the groove 85, the valve cage is formed with anexternal peripheral groove 99 communicating with a peripheral series ofports I86 leading to the bore 81, and with the mouth of the passage 66.Said cage is further formed with a peripheral series of ports I62leading from the bore 81 to an external peripheral groove I83 formed inthe valve cage and communicating with a discharge port I84 at theopposite end of the valve housing.

It will be seen that, if the valve 88 is shifted to the right from theposition illustrated in Fig. '7, fluid may flow from the fitting 48through the pipe 5| and port 16 into the bore 1! of the tube 15, andthencethrough port 18 into supply tube enlargement l9, whence fluid willflow, through passage 82, groove 85, ports 86, bore 81, ports 93, andgroove 94, and thence through passages 65 and 61 into the right-hand endof cylinder 33, tending to move said cylinder 33 to the right.Simultaneously, liquid will fiow from the lefthand end of cylinder 33,through passages 68 and 66, groove 99, and ports I60 into bore 81, andthence through ports I62, groove Hi3 and outlet port I34 back into thereservoir 35.

The movement of the cylinder 33 toward the right, consequent upon suchadjustment of the valve, will carry with it the valve housing 1|,thereby shifting the ports 93 and I80 with respect to the valve 88, toclose said ports once more.

Obviously, adjustment of the valve toward the left will similarly openports Hill and 93 to provide communication between the passage 82 andthe passage 6'6, and to provide communication between the passage 65 andthe discharge port 98, causing movement of the cylinder 33 toward theleft.

It will be clear that movement of the cylinder 33 toward the right willshift the disc 53 toward the disc I2 to squeeze the belt l9 outwardlybetween said discs, thereby pulling the belt more deeply between thediscs l6 and I! to force the disc I! to move toward the right, wherebythe speed ratio of the transmission will be increased. Similarly,movement of the cylinder 33 toward the left will shift the disc l3 awayfrom the disc 12, whereupon the spring It will be permitted to force thedisc I! toward the disc it, to decrease the speed ratio of thetransmission.

The valve 83 is provided with a projecting stem I95 to which isconnected an arm 95 mounted upon a rock shaft Nil, adapted to be moved,in one direction or the other, by a safety shifter of well known type,indicated generally by the reference numeral I88.

I claim as my invention:

1. In combination, a variable speed transmission comprising a casing, adriving shaft rotatably positioned in said casing, an expansible -V-pulley on said driving shaft and comprising two oppositely facing coneddiscs, at least one of said discs being axially shiftable, a drivenshaft rotatably positioned in said casing, an expansible V- pulley onsaid driven shaft and comprising two oppositely facing coned discs, atleast one of said discs being axially movable, a V-belt providing adriving connection between said V-pulleys, said casing being providedwith an aperture in its wall adjacent one of said shiftable discs andmeans for shifting said one disc, comprising a housing, a fluid pump insaid housing, and a fluid motor in said housing, said housing beingformed with an aperture in one wall and being secured to said casingwith said housing aperture in registry with said casing aperture, saidmotor comprising a cylinder operatively connected to said one disc, anda piston in said cylinder and fixed with respect to said housing, andmeans for controlling fluid flow from said pump to and from oppositeends of said cylinder.

2. In combination, a variable speed transmission comprising a casing, adriving shaft rotatably positioned in said casing, an expansible V-pulley on said driving shaft and comprising two oppositely facing coneddiscs, at least one of said discs being axially shiftable, a drivenshaft rotatably positioned in said casing, an expansible V-pulley onsaid driven shaft and comprising two oppositely facing coned discs, atleast one of said discs being axially movable, a V-belt providing adriving connection between said V-pulleys, said casing being providedwith an aperture in its wall adjacent one of said shiftable discs, andmeans for shifting said one disc, comprising a housing, a fluid pump insaid housing, and a fluid motor in said housing, said housing beingformed with an aperture in one wall and being secured to said casingwith said housing aperture in registry with said casing aperture, saidmotor comprising a cylinder operatively connected to said one disc, anda piston in said cylinder and fixed with respect to said housing, andmeans for controlling fluid flow from said pump to and from oppositeends of said cylinder, said last-named means comprising a group ofelements including a valve housing having ports communicating with the oosi e nd o s i li d d a po t ommu icati w th sa d pu p, nd a va vmovably mounted in said valve housingto control said ports, one of saidelements being movabl w th the c i d 3 combination, an electric motorhaving a nd e, a a n expa s l -pu y m n ed on said spindle within saidcasing and comprising a pair of mating coned discs, one of said discsbeing axially shiftable with respect to its mate, a driven shaft, aresiliently expansible V- pulley mounted on said driven shaft withinsaid casing and comprising a pair of mating coned discs, one of saiddiscs being spring-urged toward its mate, .V-belt providing a drivingconnection between said -V-pulleys, and a hydraulic control unitcomprising a housing providing a liquid reservoir, said housing beingmounted upon said casing and the interior of said housing being incommunication with the interior of said casing, pump in said housingdrawing liquid from said reservoir and supplying the same to a fluidmotor comprising a cylinder received in said housing and operativelyconnected to said firstnamed shiftable disc and a piston received insaid cylinder and fixed with respect to said housing, and means forcontrolling the flow of fluid from said pump to and from opposite endsof said cylind r.

4. In combination, an electric motor having a spindle, a casing, anexpansible V-pulley mounted on said-spindle within said casing andcomprising a pair of mating coned discs, one of said discs being axiallyshiftable with respect to its mate, a driven shaft, a second V-pulleymounted on said driven shaft within said casing and comprising a pair ofmating coned discs, one of said discs being axially shiftable withrespect to its mate, means for causing movement of said last-namedshiftable disc in response to movement of said first-named shiftabledisc, a V-belt providing a driving connection between said V-pulleys,and a hydraulic control unit comprising a housing providing a liquidreservoir, said housing being mounted upon said casing and the interiorof said housing being in communication with the interior of said casing,a pump in said housing drawing liquid from said reservoir and supplyingthe same to a fluid motor comprising a cylinder received in said housingand operatively connected to said first-named shiftable disc and apiston received in said cylinder and fixed with respect to said housing,and means for controlling the flow of fluid from said pump to and fromopposite ends of said cylinder.

5. In combination, a variable speed transmission comprising a casing, adriving shaft rotatably positioned in said casing, an expansible V-pulley on said driving shaft and comprising two oppositely facing'coneddiscs, at least one of said discs being axially shiftable, a drivenshaft rotatably positioned in said casing, an expansible V- pulley onsaid driven shaft and comprising two oppositely facing coned discs, atleast one of said discs being axially movable, a V-belt providing adriving connection between said V-pulleys, said casing being providedwith an aperture in its,

wall adjacent one of said shiftable discs, and means for shifting saidone disc, comprising a housing, a fluid pump in said housing, meansconnecting said transmission to drive said pump, and a fluid motor insaid housing, said housing being formed with an aperture in one wall andbeing secured to said casing with said housing aperture in registry withsaid casing aperture, said motor comprising a cylinder operativelyconnected to said one disc, and a piston in said cylinder and fixed withrespect to said housing, and means for controlling fluid flow from saidpump to and from opposite ends of said cylinder.

6. In combination, a variable speed transmission comprising a casing, adriving shaft rotatably positioned in said casing, an expansible V-pulley on said driving shaft and comprising two oppositely facing coneddiscs, at least one of said discs being axially shiftable, a drivenshaft rotatably positioned in said casing, an expansible V-pulley onsaid driven shaft and comprising two oppositely facing coned discs, atleast one of said discs being axially movable, a V-belt providing adriving connection between said V-pulleys, said casing being providedwith an aperture in its wall adjacent one of said shiftable discs, andmeans for shifting said one disc, comprising a housing, a fluid pump insaid housing, means providing a driving connection between said drivingshaft and said pump, and a fluid motor in said housing, said housingbeing formed with an aperture in one wall and being secured to saidcasing with said housing aperture in registry with said casing aperture,said motor comprising a cylinder operatively connected to said one disc,and a piston in said cylinder and fixed with respect to said housing,and means for controlling fluid flow from said pump to and from oppositeends of said cylinder. 7

7. In combination, an lectric motor having a spindle, a casing, anexpansible V-pulley mounted on said spindle within said casing andcomprising a pair of mating coned discs, one of said discs being axiallyshiftable with respect to its mate, a driven shaft, a resilientlyexpansible V-pulley mounted on said driven shaft within said casing andcomprising a pair of mating coned discs, one of said discs beingspring-urged toward its mate, a V-belt providing a driving connectionbetween said V-pulleys, and a hydraulic control unit comprising ahousing providing a liquid reservoir, said housing being mounted uponsaid casing and the interior of said housing being in communication withthe interior of said casing, a pump in said housing drawing liquid fromsaid reservoir and supplying the same to a fluid motor comprising acylinder received in said housing and operatively connected to saidfirst-named shiftable disc and a piston received in said cylinder andfixed with respect to said housing, meshing gears on said motor spindleand on the shaft of said pump, and means for controlling the flow offluid from said pump to and from opposite ends of said cyl-

